As per Hindu mythology these Loks (Worlds) exist in the universe – According to Srimad Bhagavad Puran (Srimad Bhagavatam)
There are billions of worlds but there are 14 + 1 types of worlds.
7 Higher level material worlds:
1. Satya-loka
Satya-loka is also known as the Brahma loka and this loka is the topmost loka in the material universe. This is the abode of truth where atmans are released from the need of rebirth.
2. Tapa-loka
This is the abode of tapas or of other Gods and Goddesses.
3. Jana-loka
This is the house of the sons of Lord Brahma.
4. Mahar-loka
This is the dwelling of great sages and laissez-faire beings like Markendeya and other rishis.
5. Svar-loka
This expanse is between the sun and the polar star. This is the heaven of Lord Indra. Indra, other Gods, Rishis, Gandharvas and Apsaras live here. This place is full of heavenly ecstasy where all the 330 million Hindu Gods (Devatas) live in along with the king of Gods, Indra.
6. Bhuvar-loka or Pitri Loka
This is the place of the Sun, planets, stars and the space between earth and the Sun. It is an actual region, the atmosphere, the place of soul and essence.
7. Bhur-loka
This is the place where the Earth dwells. According to the Vishnu Purana the earth is simply one of thousands of billions of occupied worlds like itself located in the Universe.
7 Lower level material worlds:
1. Atala-loka
This loka is ruled by Bala, son of Maya who enjoys supernatural powers.
2. Vitala-loka
This Loka is ruled by the God Hara-Bhava an incarnation of Lord Shiva. The residents of this dominion are decorated with gold from this region.
3. Sutala-loka
Sutala is the kingdom of the virtuous demon king Mahabali.
4. Talatala-loka
This loka is the kingdom of the demon-architect Maya, who is well-versed in necromancy.
5. Mahatala-loka
Mahatala is the abode of many-hooded Nagas, the sons of Kadru lead by Krodhavasha band of Kuhaka, Taksshaka, Kaliya and Sushena.
6. Rasatala-loka
This is the home of the Danavas and Daityas, who are the everlasting foes of Devatas.
7. Patala-loka
The lowest territory of the materialistic universe is called Patala or Nagaloka. Vasuki is the ruler of this Naga region. Here live quite a lot of Nagas.
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VAIKUNTHA (Completely spiritual, outside all the material cosmos)
It is the abode of Narayana, The Supreme Lord. The Supreme Creator, Preserver and Destroyer. Cause of all causes, Seed of all existences.
It has 7 entrances from front and 1 entrances from back. Total 8 entrances.
One who surrenders or submit his will to the Lotus feet of Narayana/Vishnu shall go there. It is the ultimate and supreme destination. Highest abode of all, supreme Goal of all Hindus.